[PATCH v1 1/3] dt: bindings: add documentation for zx2967 family reset controller

[PATCH v1 1/3] dt: bindings: add documentation for zx2967 family reset controller

[Baoyou Xie]

This patch adds dt-binding documentation for zx2967 family
reset controller.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
---
 .../devicetree/bindings/reset/zte,zx2967-reset.txt   | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/zte,zx2967-reset.txt

diff --git a/Documentation/devicetree/bindings/reset/zte,zx2967-reset.txt b/Documentation/devicetree/bindings/reset/zte,zx2967-reset.txt
new file mode 100644
index 0000000..22d590e
--- /dev/null
+++ b/Documentation/devicetree/bindings/reset/zte,zx2967-reset.txt
@@ -0,0 +1,20 @@
+ZTE zx2967 SoCs Reset Controller
+=======================================
+
+Please also refer to reset.txt in this directory for common reset
+controller binding usage.
+
+Required properties:
+- compatible: should be one of the following.
+	* zte,zx296718-reset
+- reg: physical base address of the controller and length of memory mapped
+	region.
+- #reset-cells: must be 1.
+
+example:
+
+	toprst: reset@1461060 {
+		compatible = "zte,zx296718-reset";
+		reg = <0x01461060 0x8>;
+		#reset-cells = <1>;
+	};
-- 
2.7.4

[PATCH v1 2/3] MAINTAINERS: add zx2967 reset controller driver to ARM ZTE architecture

[Baoyou Xie]

Add the zx2967 reset controller driver as maintained by ARM ZTE
architecture maintainers, as they're parts of the core IP.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
---
 MAINTAINERS | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 2793808..08f8155 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1980,10 +1980,12 @@ L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 F:	arch/arm/mach-zx/
 F:	drivers/clk/zte/
+F:	drivers/reset/reset-zx2967.c
 F:	drivers/soc/zte/
 F:	drivers/thermal/zx*
 F:	Documentation/devicetree/bindings/arm/zte.txt
 F:	Documentation/devicetree/bindings/clock/zx296702-clk.txt
+F:	Documentation/devicetree/bindings/reset/zte,zx2967-reset.txt
 F:	Documentation/devicetree/bindings/soc/zte/
 F:	Documentation/devicetree/bindings/thermal/zx*
 F:	include/dt-bindings/soc/zx*.h
-- 
2.7.4

[PATCH v1 3/3] reset: zx2967: add reset controller driver for ZTE's zx2967 family

[Baoyou Xie]

This patch adds reset controller driver for ZTE's zx2967 family.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
---
 drivers/reset/Kconfig        |   6 ++
 drivers/reset/Makefile       |   1 +
 drivers/reset/reset-zx2967.c | 136 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 143 insertions(+)
 create mode 100644 drivers/reset/reset-zx2967.c

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 172dc96..972d077 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -92,6 +92,12 @@ config RESET_ZYNQ
 	help
 	  This enables the reset controller driver for Xilinx Zynq SoCs.
 
+config RESET_ZX2967
+	bool "ZX2967 Reset Driver"
+	depends on ARCH_ZX || COMPILE_TEST
+	help
+	  This enables the reset controller driver for ZTE zx2967 family.
+
 source "drivers/reset/sti/Kconfig"
 source "drivers/reset/hisilicon/Kconfig"
 source "drivers/reset/tegra/Kconfig"
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 13b346e..807b77b 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -14,3 +14,4 @@ obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
 obj-$(CONFIG_TI_SYSCON_RESET) += reset-ti-syscon.o
 obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
 obj-$(CONFIG_RESET_ZYNQ) += reset-zynq.o
+obj-$(CONFIG_RESET_ZX2967) += reset-zx2967.o
diff --git a/drivers/reset/reset-zx2967.c b/drivers/reset/reset-zx2967.c
new file mode 100644
index 0000000..63f9c41
--- /dev/null
+++ b/drivers/reset/reset-zx2967.c
@@ -0,0 +1,136 @@
+/*
+ * ZTE's zx2967 family thermal sensor driver
+ *
+ * Copyright (C) 2017 ZTE Ltd.
+ *
+ * Author: Baoyou Xie <baoyou.xie@linaro.org>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+
+struct zx2967_reset {
+	void __iomem			*reg_base;
+	spinlock_t			lock;
+	struct reset_controller_dev	rcdev;
+};
+
+static int zx2967_reset_assert(struct reset_controller_dev *rcdev,
+			   unsigned long id)
+{
+	struct zx2967_reset *reset = NULL;
+	int bank = id / 32;
+	int offset = id % 32;
+	unsigned int reg;
+	unsigned long flags;
+
+	reset = container_of(rcdev, struct zx2967_reset, rcdev);
+
+	spin_lock_irqsave(&reset->lock, flags);
+
+	reg = readl(reset->reg_base + (bank * 4));
+	writel(reg & ~BIT(offset), reset->reg_base + (bank * 4));
+	reg = readl(reset->reg_base + (bank * 4));
+
+	spin_unlock_irqrestore(&reset->lock, flags);
+
+	return 0;
+}
+
+static int zx2967_reset_deassert(struct reset_controller_dev *rcdev,
+			     unsigned long id)
+{
+	struct zx2967_reset *reset = NULL;
+	int bank = id / 32;
+	int offset = id % 32;
+	unsigned int reg;
+	unsigned long flags;
+
+	reset = container_of(rcdev, struct zx2967_reset, rcdev);
+
+	spin_lock_irqsave(&reset->lock, flags);
+
+	reg = readl(reset->reg_base + (bank * 4));
+	writel(reg | BIT(offset), reset->reg_base + (bank * 4));
+	reg = readl(reset->reg_base + (bank * 4));
+
+	spin_unlock_irqrestore(&reset->lock, flags);
+
+	return 0;
+}
+
+static struct reset_control_ops zx2967_reset_ops = {
+	.assert		= zx2967_reset_assert,
+	.deassert	= zx2967_reset_deassert,
+};
+
+static int zx2967_reset_probe(struct platform_device *pdev)
+{
+	struct zx2967_reset *reset;
+	struct resource *res;
+
+	reset = devm_kzalloc(&pdev->dev, sizeof(*reset), GFP_KERNEL);
+	if (!reset)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	reset->reg_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(reset->reg_base))
+		return PTR_ERR(reset->reg_base);
+
+	spin_lock_init(&reset->lock);
+
+	reset->rcdev.owner = THIS_MODULE;
+	reset->rcdev.nr_resets = resource_size(res) * 8;
+	reset->rcdev.ops = &zx2967_reset_ops;
+	reset->rcdev.of_node = pdev->dev.of_node;
+
+	dev_info(&pdev->dev, "reset controller cnt:%d",
+		  reset->rcdev.nr_resets);
+
+	return reset_controller_register(&reset->rcdev);
+}
+
+static int zx2967_reset_remove(struct platform_device *pdev)
+{
+	struct zx2967_reset *reset = platform_get_drvdata(pdev);
+
+	reset_controller_unregister(&reset->rcdev);
+
+	return 0;
+}
+
+static const struct of_device_id zx2967_reset_dt_ids[] = {
+	 { .compatible = "zte,zx296718-reset", },
+	 {},
+};
+MODULE_DEVICE_TABLE(of, zx2967_reset_dt_ids);
+
+static struct platform_driver zx2967_reset_driver = {
+	.probe	= zx2967_reset_probe,
+	.remove	= zx2967_reset_remove,
+	.driver = {
+		.name		= "zx2967-reset",
+		.of_match_table	= zx2967_reset_dt_ids,
+	},
+};
+
+static int __init zx2967_reset_init(void)
+{
+	return platform_driver_register(&zx2967_reset_driver);
+}
+arch_initcall(zx2967_reset_init);
+
+static void __exit zx2967_reset_exit(void)
+{
+	platform_driver_unregister(&zx2967_reset_driver);
+}
+module_exit(zx2967_reset_exit);
+
+MODULE_AUTHOR("Baoyou Xie <baoyou.xie@linaro.org>");
+MODULE_DESCRIPTION("ZTE zx2967 Reset Controller Driver");
+MODULE_LICENSE("GPL");
-- 
2.7.4

Re: [PATCH v1 1/3] dt: bindings: add documentation for zx2967 family reset controller

[Shawn Guo]

On Sat, Jan 14, 2017 at 03:05:28PM +0800, Baoyou Xie wrote:
> This patch adds dt-binding documentation for zx2967 family
> reset controller.
> 
> Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>

Reviewed-by: Shawn Guo <shawnguo@kernel.org>

Re: [PATCH v1 3/3] reset: zx2967: add reset controller driver for ZTE's zx2967 family

[Shawn Guo]

On Sat, Jan 14, 2017 at 03:05:30PM +0800, Baoyou Xie wrote:
> This patch adds reset controller driver for ZTE's zx2967 family.
> 
> Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
> ---
>  drivers/reset/Kconfig        |   6 ++
>  drivers/reset/Makefile       |   1 +
>  drivers/reset/reset-zx2967.c | 136 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 143 insertions(+)
>  create mode 100644 drivers/reset/reset-zx2967.c
> 
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index 172dc96..972d077 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -92,6 +92,12 @@ config RESET_ZYNQ
>  	help
>  	  This enables the reset controller driver for Xilinx Zynq SoCs.
>  
> +config RESET_ZX2967
> +	bool "ZX2967 Reset Driver"
> +	depends on ARCH_ZX || COMPILE_TEST
> +	help
> +	  This enables the reset controller driver for ZTE zx2967 family.
> +

The config options seem to be sorted alphabetically, so RESET_ZX2967
should be put before RESET_ZYNQ.

>  source "drivers/reset/sti/Kconfig"
>  source "drivers/reset/hisilicon/Kconfig"
>  source "drivers/reset/tegra/Kconfig"
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index 13b346e..807b77b 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -14,3 +14,4 @@ obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
>  obj-$(CONFIG_TI_SYSCON_RESET) += reset-ti-syscon.o
>  obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
>  obj-$(CONFIG_RESET_ZYNQ) += reset-zynq.o
> +obj-$(CONFIG_RESET_ZX2967) += reset-zx2967.o

Ditto

> diff --git a/drivers/reset/reset-zx2967.c b/drivers/reset/reset-zx2967.c
> new file mode 100644
> index 0000000..63f9c41
> --- /dev/null
> +++ b/drivers/reset/reset-zx2967.c
> @@ -0,0 +1,136 @@
> +/*
> + * ZTE's zx2967 family thermal sensor driver
> + *
> + * Copyright (C) 2017 ZTE Ltd.
> + *
> + * Author: Baoyou Xie <baoyou.xie@linaro.org>
> + *
> + * License terms: GNU General Public License (GPL) version 2
> + */
> +
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset-controller.h>
> +
> +struct zx2967_reset {
> +	void __iomem			*reg_base;
> +	spinlock_t			lock;
> +	struct reset_controller_dev	rcdev;
> +};
> +
> +static int zx2967_reset_assert(struct reset_controller_dev *rcdev,
> +			   unsigned long id)
> +{
> +	struct zx2967_reset *reset = NULL;
> +	int bank = id / 32;
> +	int offset = id % 32;
> +	unsigned int reg;
> +	unsigned long flags;
> +
> +	reset = container_of(rcdev, struct zx2967_reset, rcdev);
> +
> +	spin_lock_irqsave(&reset->lock, flags);
> +
> +	reg = readl(reset->reg_base + (bank * 4));
> +	writel(reg & ~BIT(offset), reset->reg_base + (bank * 4));
> +	reg = readl(reset->reg_base + (bank * 4));
> +
> +	spin_unlock_irqrestore(&reset->lock, flags);
> +
> +	return 0;
> +}
> +
> +static int zx2967_reset_deassert(struct reset_controller_dev *rcdev,
> +			     unsigned long id)
> +{
> +	struct zx2967_reset *reset = NULL;
> +	int bank = id / 32;
> +	int offset = id % 32;
> +	unsigned int reg;
> +	unsigned long flags;
> +
> +	reset = container_of(rcdev, struct zx2967_reset, rcdev);
> +
> +	spin_lock_irqsave(&reset->lock, flags);
> +
> +	reg = readl(reset->reg_base + (bank * 4));
> +	writel(reg | BIT(offset), reset->reg_base + (bank * 4));
> +	reg = readl(reset->reg_base + (bank * 4));
> +
> +	spin_unlock_irqrestore(&reset->lock, flags);
> +
> +	return 0;
> +}
> +
> +static struct reset_control_ops zx2967_reset_ops = {
> +	.assert		= zx2967_reset_assert,
> +	.deassert	= zx2967_reset_deassert,
> +};
> +
> +static int zx2967_reset_probe(struct platform_device *pdev)
> +{
> +	struct zx2967_reset *reset;
> +	struct resource *res;
> +
> +	reset = devm_kzalloc(&pdev->dev, sizeof(*reset), GFP_KERNEL);
> +	if (!reset)
> +		return -ENOMEM;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	reset->reg_base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(reset->reg_base))
> +		return PTR_ERR(reset->reg_base);
> +
> +	spin_lock_init(&reset->lock);
> +
> +	reset->rcdev.owner = THIS_MODULE;
> +	reset->rcdev.nr_resets = resource_size(res) * 8;
> +	reset->rcdev.ops = &zx2967_reset_ops;
> +	reset->rcdev.of_node = pdev->dev.of_node;
> +
> +	dev_info(&pdev->dev, "reset controller cnt:%d",
> +		  reset->rcdev.nr_resets);
> +
> +	return reset_controller_register(&reset->rcdev);

Use devm_reset_controller_register(), then we can save the call to
reset_controller_unregister().

Shawn

> +}
> +
> +static int zx2967_reset_remove(struct platform_device *pdev)
> +{
> +	struct zx2967_reset *reset = platform_get_drvdata(pdev);
> +
> +	reset_controller_unregister(&reset->rcdev);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id zx2967_reset_dt_ids[] = {
> +	 { .compatible = "zte,zx296718-reset", },
> +	 {},
> +};
> +MODULE_DEVICE_TABLE(of, zx2967_reset_dt_ids);
> +
> +static struct platform_driver zx2967_reset_driver = {
> +	.probe	= zx2967_reset_probe,
> +	.remove	= zx2967_reset_remove,
> +	.driver = {
> +		.name		= "zx2967-reset",
> +		.of_match_table	= zx2967_reset_dt_ids,
> +	},
> +};
> +
> +static int __init zx2967_reset_init(void)
> +{
> +	return platform_driver_register(&zx2967_reset_driver);
> +}
> +arch_initcall(zx2967_reset_init);
> +
> +static void __exit zx2967_reset_exit(void)
> +{
> +	platform_driver_unregister(&zx2967_reset_driver);
> +}
> +module_exit(zx2967_reset_exit);
> +
> +MODULE_AUTHOR("Baoyou Xie <baoyou.xie@linaro.org>");
> +MODULE_DESCRIPTION("ZTE zx2967 Reset Controller Driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.7.4
> 

Re: [PATCH v1 3/3] reset: zx2967: add reset controller driver for ZTE's zx2967 family

[Shawn Guo]

On Sat, Jan 14, 2017 at 03:05:30PM +0800, Baoyou Xie wrote:
> +static int zx2967_reset_assert(struct reset_controller_dev *rcdev,
> +			   unsigned long id)
> +{
> +	struct zx2967_reset *reset = NULL;
> +	int bank = id / 32;
> +	int offset = id % 32;
> +	unsigned int reg;

u32 is probably better for register value.

> +	unsigned long flags;
> +
> +	reset = container_of(rcdev, struct zx2967_reset, rcdev);
> +
> +	spin_lock_irqsave(&reset->lock, flags);
> +
> +	reg = readl(reset->reg_base + (bank * 4));
> +	writel(reg & ~BIT(offset), reset->reg_base + (bank * 4));
> +	reg = readl(reset->reg_base + (bank * 4));

Is this read on the register is necessary?  If so, we should probably
have a comment for that.

> +
> +	spin_unlock_irqrestore(&reset->lock, flags);
> +
> +	return 0;
> +}
> +
> +static int zx2967_reset_deassert(struct reset_controller_dev *rcdev,
> +			     unsigned long id)

Please indent the line right after parentheses.

> +{
> +	struct zx2967_reset *reset = NULL;
> +	int bank = id / 32;
> +	int offset = id % 32;
> +	unsigned int reg;
> +	unsigned long flags;
> +
> +	reset = container_of(rcdev, struct zx2967_reset, rcdev);
> +
> +	spin_lock_irqsave(&reset->lock, flags);
> +
> +	reg = readl(reset->reg_base + (bank * 4));
> +	writel(reg | BIT(offset), reset->reg_base + (bank * 4));
> +	reg = readl(reset->reg_base + (bank * 4));
> +
> +	spin_unlock_irqrestore(&reset->lock, flags);
> +
> +	return 0;
> +}

Only difference between these two functions is only one line.  Should we
consolidate them a bit?

Shawn

Re: [PATCH v1 1/3] dt: bindings: add documentation for zx2967 family reset controller

[Philipp Zabel]

Hi,

On Sat, 2017-01-14 at 15:05 +0800, Baoyou Xie wrote:
> This patch adds dt-binding documentation for zx2967 family
> reset controller.
> 
> Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
> ---
>  .../devicetree/bindings/reset/zte,zx2967-reset.txt   | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/reset/zte,zx2967-reset.txt
> 
> diff --git a/Documentation/devicetree/bindings/reset/zte,zx2967-reset.txt b/Documentation/devicetree/bindings/reset/zte,zx2967-reset.txt
> new file mode 100644
> index 0000000..22d590e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/reset/zte,zx2967-reset.txt
> @@ -0,0 +1,20 @@
> +ZTE zx2967 SoCs Reset Controller
> +=======================================
> +
> +Please also refer to reset.txt in this directory for common reset
> +controller binding usage.
> +
> +Required properties:
> +- compatible: should be one of the following.
> +	* zte,zx296718-reset
> +- reg: physical base address of the controller and length of memory mapped
> +	region.
> +- #reset-cells: must be 1.
> +
> +example:
> +
> +	toprst: reset@1461060 {

That node should be named reset-controller.

> +		compatible = "zte,zx296718-reset";
> +		reg = <0x01461060 0x8>;
> +		#reset-cells = <1>;
> +	};

regards
Philipp

Re: [PATCH v1 3/3] reset: zx2967: add reset controller driver for ZTE's zx2967 family

[Philipp Zabel]

On Sat, 2017-01-14 at 15:05 +0800, Baoyou Xie wrote:
> This patch adds reset controller driver for ZTE's zx2967 family.
> 
> Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
> ---
>  drivers/reset/Kconfig        |   6 ++
>  drivers/reset/Makefile       |   1 +
>  drivers/reset/reset-zx2967.c | 136 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 143 insertions(+)
>  create mode 100644 drivers/reset/reset-zx2967.c
> 
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index 172dc96..972d077 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -92,6 +92,12 @@ config RESET_ZYNQ
>  	help
>  	  This enables the reset controller driver for Xilinx Zynq SoCs.
>  
> +config RESET_ZX2967
> +	bool "ZX2967 Reset Driver"
> +	depends on ARCH_ZX || COMPILE_TEST
> +	help
> +	  This enables the reset controller driver for ZTE zx2967 family.
> +
>  source "drivers/reset/sti/Kconfig"
>  source "drivers/reset/hisilicon/Kconfig"
>  source "drivers/reset/tegra/Kconfig"
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index 13b346e..807b77b 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -14,3 +14,4 @@ obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
>  obj-$(CONFIG_TI_SYSCON_RESET) += reset-ti-syscon.o
>  obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
>  obj-$(CONFIG_RESET_ZYNQ) += reset-zynq.o
> +obj-$(CONFIG_RESET_ZX2967) += reset-zx2967.o
> diff --git a/drivers/reset/reset-zx2967.c b/drivers/reset/reset-zx2967.c
> new file mode 100644
> index 0000000..63f9c41
> --- /dev/null
> +++ b/drivers/reset/reset-zx2967.c
> @@ -0,0 +1,136 @@
> +/*
> + * ZTE's zx2967 family thermal sensor driver

This description is incorrect.

> + *
> + * Copyright (C) 2017 ZTE Ltd.
> + *
> + * Author: Baoyou Xie <baoyou.xie@linaro.org>
> + *
> + * License terms: GNU General Public License (GPL) version 2
> + */
> +
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset-controller.h>
> +
> +struct zx2967_reset {
> +	void __iomem			*reg_base;
> +	spinlock_t			lock;
> +	struct reset_controller_dev	rcdev;
> +};
> +
> +static int zx2967_reset_assert(struct reset_controller_dev *rcdev,
> +			   unsigned long id)
> +{
> +	struct zx2967_reset *reset = NULL;
> +	int bank = id / 32;
> +	int offset = id % 32;
> +	unsigned int reg;
> +	unsigned long flags;
> +
> +	reset = container_of(rcdev, struct zx2967_reset, rcdev);
> +
> +	spin_lock_irqsave(&reset->lock, flags);
> +
> +	reg = readl(reset->reg_base + (bank * 4));
> +	writel(reg & ~BIT(offset), reset->reg_base + (bank * 4));
> +	reg = readl(reset->reg_base + (bank * 4));
> +
> +	spin_unlock_irqrestore(&reset->lock, flags);
> +
> +	return 0;
> +}
> +
> +static int zx2967_reset_deassert(struct reset_controller_dev *rcdev,
> +			     unsigned long id)
> +{
> +	struct zx2967_reset *reset = NULL;
> +	int bank = id / 32;
> +	int offset = id % 32;
> +	unsigned int reg;
> +	unsigned long flags;
> +
> +	reset = container_of(rcdev, struct zx2967_reset, rcdev);
> +
> +	spin_lock_irqsave(&reset->lock, flags);
> +
> +	reg = readl(reset->reg_base + (bank * 4));
> +	writel(reg | BIT(offset), reset->reg_base + (bank * 4));
> +	reg = readl(reset->reg_base + (bank * 4));
> +
> +	spin_unlock_irqrestore(&reset->lock, flags);
> +
> +	return 0;
> +}
> +
> +static struct reset_control_ops zx2967_reset_ops = {
> +	.assert		= zx2967_reset_assert,
> +	.deassert	= zx2967_reset_deassert,
> +};
> +
> +static int zx2967_reset_probe(struct platform_device *pdev)
> +{
> +	struct zx2967_reset *reset;
> +	struct resource *res;
> +
> +	reset = devm_kzalloc(&pdev->dev, sizeof(*reset), GFP_KERNEL);
> +	if (!reset)
> +		return -ENOMEM;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	reset->reg_base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(reset->reg_base))
> +		return PTR_ERR(reset->reg_base);
> +
> +	spin_lock_init(&reset->lock);
> +
> +	reset->rcdev.owner = THIS_MODULE;
> +	reset->rcdev.nr_resets = resource_size(res) * 8;
> +	reset->rcdev.ops = &zx2967_reset_ops;
> +	reset->rcdev.of_node = pdev->dev.of_node;
> +
> +	dev_info(&pdev->dev, "reset controller cnt:%d",
> +		  reset->rcdev.nr_resets);
> +
> +	return reset_controller_register(&reset->rcdev);

As Shawn suggested, use the devm_ variant here. It allows you to drop
the remove function below.

> +}
> +
> +static int zx2967_reset_remove(struct platform_device *pdev)
> +{
> +	struct zx2967_reset *reset = platform_get_drvdata(pdev);
> +
> +	reset_controller_unregister(&reset->rcdev);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id zx2967_reset_dt_ids[] = {
> +	 { .compatible = "zte,zx296718-reset", },
> +	 {},
> +};
> +MODULE_DEVICE_TABLE(of, zx2967_reset_dt_ids);
> +
> +static struct platform_driver zx2967_reset_driver = {
> +	.probe	= zx2967_reset_probe,
> +	.remove	= zx2967_reset_remove,
> +	.driver = {
> +		.name		= "zx2967-reset",
> +		.of_match_table	= zx2967_reset_dt_ids,
> +	},
> +};
> +
> +static int __init zx2967_reset_init(void)
> +{
> +	return platform_driver_register(&zx2967_reset_driver);
> +}
> +arch_initcall(zx2967_reset_init);
> +
> +static void __exit zx2967_reset_exit(void)
> +{
> +	platform_driver_unregister(&zx2967_reset_driver);
> +}
> +module_exit(zx2967_reset_exit);
> +
> +MODULE_AUTHOR("Baoyou Xie <baoyou.xie@linaro.org>");
> +MODULE_DESCRIPTION("ZTE zx2967 Reset Controller Driver");
> +MODULE_LICENSE("GPL");

regards
Philipp